Throw-off for printing-presses



(No Model.)

J. E. LEE. THROW-OFF FOR PRINTING PRESSES.

Patented July 20, 1897.

UNITED STATES 1 ATENT Erica JAMES EDGAR LEE, OFCHICAGO, ILLINOIS.

-THROW-OFF FOR PRlNTlNG-PRESSES.

SPECIFICATION forming part of Letters Patent No. 586,931, dated July 20, 1897.

Application filed June 2'7, 1896- To all whom it may concern.-

Be it known that I, JAMES EDGAR LEE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Throw-Offs for Printing- Presses, of which the following is a full, clear, and exact specification.

This invention relates to throwoffs for printing-presses to enable the pressman toprevent an impression at any time during the running of the press, and it is more particularly designed as an improvement upon devices of this character in which the back shaft or eccentric-shaft, usually journaled in the back legs, is actuated to change the stroke of the back legs through the instrumentality of a rod pivoted at one end to a crank formed on or secured to the eccentric-shaft and having its other end connected with some means of operation, such as an ordinary hand-lever.

In order to render the device precise and accurate in operation, mechanism of some kind is necessary to limit the throw of the actuating-lever and lock the parts in the position in which they have been set. Ordinarily the parts are so constructed as to look when the impression is thrown on and thus insure against Working off; but practice has demonstrated that it is equally important that the mechanism should be so locked also in its thrown-01f position to prevent it from working on. With devices of this character it has also been found in practice that the oscillation of the back legs imparts a to-and-fro rotary or oscillatory movement to the back shaft or eccentric-shaft by reason of the rod to which the crank on the back shaft is connected having a different center at its lower end from the center on which the back legs are pivoted. This motion of the back shaft or eccentric-shaft, though slight at each stroke of the back legs; nevertheless Wears away the bearings of the back shaft to a material extent in a very short while 'and thereby renders the parts loose and seriously impairs the efficiency of the press.

One of the objects of my invention, therefore, is to provide improved means for causing the parts to become automatically locked in either position in which they mayhave been set or thrown.

Serial No. 597,137. (No model.)

Another object of my invention is to provide improved and simple mechanism for shifting the eccentric shaft or back shaft when it is desired to throw the impression on or off'and at the same time avoid any inde= pendent rotary movement of the eccentricshaft or back shaft during the operation of the press with the impression either on or off.

\Vith these ends in view my invention consists in certain features of novelty in the construction, combination, and arrangement of parts by which the said objects and certain other objects hereinafter appearing are accomplished, all as fully described with reference to the accompanying drawings, and more particularly pointed out in the claims.

In the said drawings, Figure 1 is a side elevation of a portion of a printing-press provided with my improved throw-off, the back legs being shown at the extremity of their forward movement in dotted lines and the im pression being on. Fig. 2 is a similar View showing the impression thrown off. Fig. 3 is a detail edge vieWof one of the connectingrods hereinafter described; and Fig. 4 is a detail plan View of abell-crank lever and connected parts pivoted to the frame of the press, the frame being shown in section.

In carrying out my invention the movable or vibrating part of the impression mechanism, usually the vibrating back legs, is provided witha shiftable connection with the operating mechanism of the press, such shiftable connection usually being in the form of the ordinary back shaft or eccentric-shaft, whereby the distance between the point of connection with such operating mechanism and said vibrating part or back legs may be increased or diminished in order to prevent the form from coming against the platen when desired, and to this shiftable connection or back shaft is pivoted the upper end of an actuating-rod Whose lower end is permanently pivoted concentrically with the pivot of the back legs and yet shiftable lengthwise with reference to its own pivotal point, and to this rod is connected suitable automatically-locking mechanismfor raising and lowering it and thus shifting or partially rotating the back shaft or eccentric-shaft and throwing the impression on or off.

In the drawings, in which my invention is shown as applied to that class of presses in which the platen is stationary, 1 represents the main frame; 2, the vibrating back legs; 3, the eccentric-shaft or back shaft, which is journaled as usual in any suitable enlargement at 011 the back legs. 5 is the shaft or pivotal axis of the back legs, which may be journaled in the main frame 1, as usual, and b is the usual crank-disk, having wrist-pin 7, connected by connecting-rod 8 with wrist-pin 9 of the eccentric-shaft or back shaft 3. All of these parts may be of the usual or any suitable construction.

The eceentric-shaft or back shaft 3 is provided with a side lug 10, which in effect is a crank-arm and to which is pivoted the upper end of an actuating-rod 11, whose lower end is pivoted concentrically with the axis or shaft 5 of the back leg. 2 in such a manner that the actuating-rod 11 may rise and fall for shifting the eccentric-shaft or back shaft This pivotal attachment of the lower end of the actuating-rod 11 may be best accomplished by providing the same with a verticallyelongated passage or opening 12, which embraces the outer end of the shaft 5, or, which would of course be the equivalent thereof, a lug or pivot-pin projecting from the frame 1 and being arranged concentrically with the shaft 5. \Vith this construction it will be seen that the back legs 2 and the actuating-rod ll vibrate in unison, and the extent of their movement is precisely the same whether the impression be 011 or off, and consequently the shaft 3 is absolutely free from independent movement or rotation, excepting at such times when it is shifted by the raising or lowering of the rod 11 for changing the impression, and hence the aforesaid objectionable continual independent oscillation of the shaft 3, produced by the vibratory action of the back legs, is prevented.

The lower end of the actuating-rod 11 is provided with a boss 13, from the outer end of which projects an upwardly-extendinglip ll, which forms means for the pivotal con nection of a link 15, whose upper end is pivoted to a lever 10, which in turn is secured by pivotal connection to the main frame 1 and is also pivotally connected at about its mid-length to the lower end of a link 18. Theupper end of the link 18 is pivotallyconneeted at 19 with the lower arm 20 of a bellcrank lever 21, whose other arm 22 is pivoted at 23 to the lower end of a connecting-rod 24. The upper end of this connecting-rod 2t is pivotally attached at 25 to a hand operatinglevcr 26, which is pivotally supported at 27 upon the main frame or other suitable part of the press. 'ly this construction it will be seen that when the operating lever 26 is pulled toward the pressman into the position shown in Fig. l the lower arm of the bellcrank 21 is raised from theposition shown in Fig. 2 to that shown in Fig. 1 and the actuating-rod 11 for the eceentrie-shaft is also elevated and the impression thrown on by reason of the larger side of the eccentric-shaft- 3 being placed between the pivotal points 7 and 9, but the pivotal point of the lower end of the rod 11 nevertheless remains concentric with the shaft 5 or pivotal point of the back legs 2, inasmuch as the end of the shaft 5, (or other lug concentric thcrewith,) projecting into the slot 12, does not change its position with the rod 11.

The parts are so proportioned that when they are in the described thrown-on position the pivotal point of the'link 15 will be concentric with the pivotal point'of the rod 11, and consequently the oscillation of such rod 1 1 cannotimpart any movement whatever to the link 15, andhence the vibratory action of the back legs cannot tend in the least degree to alter the position of the operating-lever 26, and therefore such lever will remain in the position in which it is thrown and there will be no danger of the impression working off. In order, however, that the weight of the connections between the rod 11.

and the lever may not tend to depress the rod 11 and thus throw the impression off, some suitable means of automatically holding the connecting-rod 2-1 against downward movement may be provided. This means preferably consists of a bend 28 in the connecting-rod 24, which carries the pivotal point back of a straight line passing through the pivotal points 23 and 27, and consequently the weight of the rod 2% tends to lock the lever 26 against forward movement and absolutely prevents any downward pressure on the rod 1.1 from the connections at the lowerend thereof.

lVhen it is desired to throw the impression off, the operating-lever 2G is shifted from the posit-ion shown in Fig. 1 to that shown. in Fig. 2. This depresses the upper arm 22 of the bell-crank 21 and also depresses the lever 16, and in so doing carries the actuating-rod 11 downward to the position indicated in Fig. 2. hen the parts are in this position and the impression is off, the pivotal point between the end of the lever 16 and the link 15 will be concentric with the pivotal point of the rod 11 and back legs 2, and it will therefore be seen that the length of the link 15, or, in other words, the distance between the pivots at its ends, is equal to the throw of the rod 11, and this throw in the downward direction is preferably limited by the upper end of the slot 12 coming against the protruding end of the shaft 5. llence it will be seen that when the impression is 011 the vibratory action of the back legs 2 and the rod 11 cannot alter the position of the lever 16 through the intermediary of the link 15, and therefore the impression will remain oil until the operatinglever 26 is again thrown to the position shown in Fig. 1. This relative proportion of the parts, which results in the described concentrie location of the pivotal points, in itself is sufiieient under ordinary circumstances to lock the parts against accidental movement and prevent the impression from working on 5 but in order to further guard against the inn-- pression working on the bell-crank lever 21 is so proportioned that the pivot 21 which connects it to the frame 1, will be in a straight line with the pivot which connects it to the upper end of the link 18 and that which connects the lower end of the link 18 with the lever 16, thus forming an absolute lock for preventing the upward movement of the lever 16.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is

1. A throw-off mechanism for printingpresses having in combination the operating mechanism of the press; the pivoted vibrating part of the impression mechanism having a shiftable connection with said operating mechanism whereby the impression may be thrown on or off; a longitudinally-movable rod connected at one end to said shiftable connection for shiftingit and having its other end confined to travel across the axis of the pivot of said vibrating part whereby said axis will at all times pass through said rod, and means for moving said rod longitudinally, substantially as set forth.

2. A throw-off mechanism for printingpresses having in combination the operating mechanism of the press; the pivoted vibrating part of the impression mechanism having a shiftable connection withsaid operating mechanism whereby the impression maybe thrown on or off; a pivot fixed concentrically with the center of vibration of said vibrating part of the impression mechanism; a longitudinally-movable rod connected at one end to said shiftable connection for shiftingit and having its other end provided with sliding connection with said fixed pivot, and means for moving said rod longitudinally adapted to lock the rod against longitudinal movement when the impression is thrown off, substantially as set forth.

3. A throw oil mechanism for printingpresses having in combination the pivoted back legs, an eccentric carried by said back legs and having connection with some operating part of the press, a shiftable rod connected with said eccentric for rotating the same and having its end pivoted concentrically with the pivot of said back legs, and being longitudinally shiftable with relation to its own pivotal point, a link pivoted to said rod and an operating-lever .connected with said link, for raising and lowering said rod, substantially as set forth.

4:. A throwoff mechanism for printingpresses having in combination the pivoted back legs, an eccentric carried by said back legs and .having connection with some operating part of the press, a shiftable rod for actuating'said eccentric, having one end pivoted concentrically with the pivot of said back legs, a link pivoted to said rod and being substantially equal in length to the throw of said rod, and, means pivoted to said link for raising and lowering it and thereby shifting said rod, substantially as set forth.

'5. A throw -off mechanism for printingpresses having in combination the pivoted back legs, an eccentric carried by said back legs and having connection with some oper- 6. A throw-off mechanism for printingpresses having in combination the pivoted back legs, an eccentric carried by said back legs and having connection with some operating part of the press, a rod for actuating said eccentric, having a slot; a pivot arranged concentrically with the pivot of said back legs and engaging in said slot; a link pivoted to said rod; a pivoted lever having one end pivoted to said link, and an operating-lever having jointed connection with said first lever, substantially as set forth.

7. A throw oft mechanism for printingpresses having in combination the pivoted back legs; an eccentric carried by said back legs and having connection with some operating part of the press; a rod for actuating said eccentric, provided with a slot; a pivot arranged concentrically with the pivot of said back legs and engaging with said slot; a link pivoted tosaid rod at one end, a lever pivoted to said rod at the other end; the distance between the pivotal points at the opposite ends of said link being substantially equal to the throw of said rod; and means for raising and lowering said lever, substantially as set forth.

8. A throw off mechanism for printingpresses having in combination the pivoted back legs; an eccentric carried by said back legs and having connection with some operating part of the press; a rod for actuating said eccentric, having aslot; a pivot arranged concentrically with the pivot of said back legs and engaging in said slot; a link pivoted to said rod at one end; a lever pivoted to the other end of said link, the distance between said pivots of said link being substantially equal to. the throw of said rod a pivoted bellcrank having one arm connected with said lever; and an operating-lever having connection with the other arm of said bell-crank, substantially as set forth.

9. A throw off mechanism 'for printingpresses having incombinationt-he pivoted back legs; an eccentric carried by said back legs and having connection with some oper ating part of the press; a rod for actuating said eccentric, havinga slot; a pivot arranged concentrically with the pivot of said back legs and engaging in said slot; a link pivoted at one end to said rod; a lever pivoted to the other end of said link, the distance between IIO the pivots of said link being substantially equal to the throw of said rod; a pivoted bellcrank; a link connecting said lever with one arm of said bell-crank; an operating-lever, and a rod connecting said operating-lever with the other end of said bell-crank, the parts being so proportioned that when the inipression is thrown off the pivotal point at the upper end of the last said rod will be back of a straight line passing through the pivotal point of said operating-lever and the pivotal connection of said bell-crank, substantially as set forth.

10. A throw-oil mechanism for printingpresses having in combination the pivoted back legs; an eccentric carried by said back legs and having connection with some operating part of the press; a rod for actuating said eccentric, having a slot; a pivot arranged concentrically with the pivot of said back legs and engaging in said slot; a link 15 pivoted to said rod at one end; the lever 16 pivoted to the other end of said link, the distance between the pivots of said link being equal to the throw of said rod; the link 18 pivoted to the lever 16; a bell-crank having one arm pivoted to said link 18; the rod 24 pivoted to the other arm of said bell-crank; the operating-lever 26 pivoted to said rod 24, and the said parts being so proportioned that when they are in their thrown-ott position the pivotal connection between the lever 26 and the rod 24 will be back of a straight line passing through the pivotal connection between the bell-crank and the rod 24 and the pivot of the lever 26; and when in the thrown-on position the pivot of the bell-crank and the pivotal connection between the lever 16, link 18 and bell-crank will be in a substantially straight line; whereby the parts will be locked in either position, substantially as set forth.

. J. EDGAR LEE.

Witnesses:

EDNA B. JOHNSON, F. A. HOPKINS. 

